/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkFlashReaderInternal.cxx

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
#include "vtkAMRFlashReaderInternal.h"

#include <vector>

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::GetBlockAttribute(
  const char* attribute, int blockIdx, vtkDataSet* pDataSet)
{
  // this function must be called by GetBlock( ... )
  this->ReadMetaData();

  if (attribute == nullptr || blockIdx < 0 || pDataSet == nullptr ||
    blockIdx >= this->NumberOfBlocks)
  {
    //   vtkDebugMacro( "Data attribute name or vtkDataSet nullptr, or " <<
    //                  "invalid block index." << endl );
    return;
  }
  // remove the prefix ("mesh_blockandlevel/" or "mesh_blockandproc/") to get
  // the actual attribute name
  std::string tempName = attribute;
  size_t slashPos = tempName.find('/');
  std::string attrName = tempName.substr(slashPos + 1);
  hid_t dataIndx = H5Dopen(this->FileIndex, attrName.c_str());

  if (dataIndx < 0)
  {
    //   vtkErrorMacro( "Invalid attribute name." << endl );
    return;
  }

  hid_t spaceIdx = H5Dget_space(dataIndx);
  hsize_t dataDims[4]; // dataDims[0] == number of blocks
  hsize_t numbDims = H5Sget_simple_extent_dims(spaceIdx, dataDims, nullptr);

  if (numbDims != 4)
  {
    //   vtkErrorMacro( "Error with reading the data dimensions." << endl );
    return;
  }

  int numTupls = dataDims[1] * dataDims[2] * dataDims[3];
  hsize_t startVec[5];
  hsize_t stridVec[5];
  hsize_t countVec[5];

  startVec[0] = blockIdx;
  startVec[1] = 0;
  startVec[2] = 0;
  startVec[3] = 0;

  stridVec[0] = 1;
  stridVec[1] = 1;
  stridVec[2] = 1;
  stridVec[3] = 1;

  countVec[0] = 1;
  countVec[1] = dataDims[1];
  countVec[2] = dataDims[2];
  countVec[3] = dataDims[3];

  // file space index
  hid_t filSpace = H5Screate_simple(4, dataDims, nullptr);
  H5Sselect_hyperslab(filSpace, H5S_SELECT_SET, startVec, stridVec, countVec, nullptr);

  startVec[0] = 0;
  startVec[1] = 0;
  startVec[2] = 0;
  startVec[3] = 0;

  stridVec[0] = 1;
  stridVec[1] = 1;
  stridVec[2] = 1;
  stridVec[3] = 1;

  countVec[0] = 1;
  countVec[1] = dataDims[1];
  countVec[2] = dataDims[2];
  countVec[3] = dataDims[3];

  hid_t memSpace = H5Screate_simple(4, dataDims, nullptr);
  H5Sselect_hyperslab(memSpace, H5S_SELECT_SET, startVec, stridVec, countVec, nullptr);

  vtkDoubleArray* dataAray = vtkDoubleArray::New();
  dataAray->SetName(attribute);
  dataAray->SetNumberOfTuples(numTupls);
  double* arrayPtr = static_cast<double*>(dataAray->GetPointer(0));

  int i;
  hid_t hRawType = H5Dget_type(dataIndx);
  hid_t dataType = H5Tget_native_type(hRawType, H5T_DIR_ASCEND);

  if (H5Tequal(dataType, H5T_NATIVE_DOUBLE))
  {
    H5Dread(dataIndx, dataType, memSpace, filSpace, H5P_DEFAULT, arrayPtr);
  }
  else if (H5Tequal(dataType, H5T_NATIVE_FLOAT))
  {
    std::vector<float> dataFlts(numTupls);
    H5Dread(dataIndx, dataType, memSpace, filSpace, H5P_DEFAULT, dataFlts.data());
    for (i = 0; i < numTupls; i++)
    {
      arrayPtr[i] = dataFlts[i];
    }
  }
  else if (H5Tequal(dataType, H5T_NATIVE_INT))
  {
    std::vector<int> dataInts(numTupls);
    H5Dread(dataIndx, dataType, memSpace, filSpace, H5P_DEFAULT, dataInts.data());
    for (i = 0; i < numTupls; i++)
    {
      arrayPtr[i] = dataInts[i];
    }
  }
  else if (H5Tequal(dataType, H5T_NATIVE_UINT))
  {
    std::vector<unsigned int> unsgnInt(numTupls);
    H5Dread(dataIndx, dataType, memSpace, filSpace, H5P_DEFAULT, unsgnInt.data());
    for (i = 0; i < numTupls; i++)
    {
      arrayPtr[i] = unsgnInt[i];
    }
  }
  else
  {
    //   vtkErrorMacro( "Invalid data attribute type." << endl );
  }

  H5Sclose(filSpace);
  H5Sclose(memSpace);
  H5Sclose(spaceIdx);
  H5Tclose(dataType);
  H5Tclose(hRawType);
  H5Dclose(dataIndx);

  pDataSet->GetCellData()->AddArray(dataAray);

  dataAray->Delete();
  dataAray = nullptr;
  arrayPtr = nullptr;
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::Init()
{
  this->FileName = nullptr;
  this->FileIndex = -1;
  this->MinBounds[0] = this->MinBounds[1] = this->MinBounds[2] = VTK_DOUBLE_MAX;
  this->MaxBounds[0] = this->MaxBounds[1] = this->MaxBounds[2] = -VTK_DOUBLE_MAX;

  this->NumberOfBlocks = 0;
  this->NumberOfLevels = 0;
  this->FileFormatVersion = -1;
  this->NumberOfParticles = 0;
  this->NumberOfLeafBlocks = 0;
  this->NumberOfDimensions = 0;
  this->NumberOfProcessors = 0;
  this->HaveProcessorsInfo = 0;
  this->BlockGridDimensions[0] = 1;
  this->BlockGridDimensions[1] = 1;
  this->BlockGridDimensions[2] = 1;
  this->BlockCellDimensions[0] = 1;
  this->BlockCellDimensions[1] = 1;
  this->BlockCellDimensions[2] = 1;
  this->NumberOfChildrenPerBlock = 0;
  this->NumberOfNeighborsPerBlock = 0;

  this->Blocks.clear();
  this->LeafBlocks.clear();
  this->AttributeNames.clear();

  this->ParticleName = "";
  this->ParticleAttributeTypes.clear();
  this->ParticleAttributeNames.clear();
  this->ParticleAttributeNamesToIds.clear();
}

//------------------------------------------------------------------------------
int vtkFlashReaderInternal::GetCycle()
{
  const bool bTmCycle = true;

  hid_t fileIndx = H5Fopen(this->FileName, H5F_ACC_RDONLY, H5P_DEFAULT);
  if (fileIndx < 0)
  {
    return -VTK_INT_MAX;
  }

  this->ReadVersionInformation(fileIndx);
  this->ReadSimulationParameters(fileIndx, bTmCycle);
  H5Fclose(fileIndx);

  return this->SimulationParameters.NumberOfTimeSteps;
}

//------------------------------------------------------------------------------
double vtkFlashReaderInternal::GetTime()
{
  const bool bTmCycle = true;

  hid_t fileIndx = H5Fopen(this->FileName, H5F_ACC_RDONLY, H5P_DEFAULT);
  if (fileIndx < 0)
  {
    return -VTK_DOUBLE_MAX;
  }

  this->ReadVersionInformation(fileIndx);
  this->ReadSimulationParameters(fileIndx, bTmCycle);
  H5Fclose(fileIndx);

  return this->SimulationParameters.Time;
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadMetaData()
{
  if (this->FileIndex >= 0)
  {
    return;
  }

  // file handle
  this->FileIndex = H5Fopen(this->FileName, H5F_ACC_RDONLY, H5P_DEFAULT);
  if (this->FileIndex < 0)
  {
    vtkGenericWarningMacro("Failed to open file " << this->FileName << "." << endl);
    return;
  }

  // file format version
  this->ReadVersionInformation(this->FileIndex);
  if (this->FileFormatVersion < FLASH_READER_FLASH3_FFV8)
  {
    this->ReadParticleAttributes(); // FLASH2 version
  }
  else
  {
    this->ReadParticleAttributesFLASH3(); // FLASH3 version
  }

  // block structures
  this->ReadBlockStructures();
  if (this->NumberOfParticles == 0 && this->NumberOfBlocks == 0)
  {
    vtkGenericWarningMacro("Invalid Flash file, without any "
      << "block/particle." << endl);
    return;
  }

  // obtain further information about blocks
  if (this->NumberOfBlocks > 0)
  {
    this->ReadBlockBounds();
    this->ReadRefinementLevels();
    this->ReadSimulationParameters(this->FileIndex);
    this->ReadDataAttributeNames();
    this->GetBlockMinMaxGlobalDivisionIds();
    this->ReadBlockTypes();
    this->ReadBlockCenters();
    this->ReadProcessorIds();
  }
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadProcessorIds()
{
  hid_t rootIndx = H5Gopen(this->FileIndex, "/");
  if (rootIndx < 0)
  {
    vtkGenericWarningMacro("Failed to open the root group" << endl);
    return;
  }

  hsize_t numbObjs;
  herr_t errorIdx = H5Gget_num_objs(rootIndx, &numbObjs);
  if (errorIdx < 0)
  {
    vtkGenericWarningMacro("Failed to get the number of objects "
      << "in the root group" << endl);
    return;
  }

  hsize_t objIndex;
  std::string sObjName = "processor number";
  char namefromfile[17];
  for (objIndex = 0; objIndex < numbObjs; objIndex++)
  {
    ssize_t objsize = H5Gget_objname_by_idx(rootIndx, objIndex, nullptr, 0);
    if (objsize == 16)
    {
      H5Gget_objname_by_idx(rootIndx, objIndex, namefromfile, 17);
      std::string tempstr = namefromfile;
      if (tempstr == sObjName) // if this file contains processor numbers
      {
        this->HaveProcessorsInfo = 1;
      }
    }
  }
  H5Gclose(rootIndx);

  if (this->HaveProcessorsInfo)
  {
    // Read the processor number description for the blocks
    hid_t procnumId = H5Dopen(this->FileIndex, "processor number");
    if (procnumId < 0)
    {
      vtkGenericWarningMacro("Processor Id information not found." << endl);
    }

    hid_t procnumSpaceId = H5Dget_space(procnumId);

    hsize_t procnum_dims[1];
    hsize_t procnum_ndims = H5Sget_simple_extent_dims(procnumSpaceId, procnum_dims, nullptr);

    if (static_cast<int>(procnum_ndims) != 1 ||
      static_cast<int>(procnum_dims[0]) != this->NumberOfBlocks)
    {
      vtkGenericWarningMacro("Error with getting the number of "
        << "processor Ids." << endl);
    }

    hid_t procnum_raw_data_type = H5Dget_type(procnumId);
    hid_t procnum_data_type = H5Tget_native_type(procnum_raw_data_type, H5T_DIR_ASCEND);

    std::vector<int> procnum_array(this->NumberOfBlocks);
    H5Dread(procnumId, procnum_data_type, H5S_ALL, H5S_ALL, H5P_DEFAULT, procnum_array.data());

    int highProcessor = -1;
    for (int b = 0; b < this->NumberOfBlocks; b++)
    {
      int pnum = procnum_array[b];
      if (pnum > highProcessor)
      {
        highProcessor = pnum;
        this->NumberOfProcessors++;
      }
      this->Blocks[b].ProcessorId = pnum;
    }

    H5Tclose(procnum_data_type);
    H5Tclose(procnum_raw_data_type);
    H5Sclose(procnumSpaceId);
    H5Dclose(procnumId);
  }
  else
  {
    this->NumberOfProcessors = 1;
    for (int b = 0; b < this->NumberOfBlocks; b++)
    {
      this->Blocks[b].ProcessorId = 0;
    }
  }
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadDoubleScalars(hid_t fileIndx)
{
  // Should only be used for FLASH3 files

  if (this->FileFormatVersion < FLASH_READER_FLASH3_FFV8)
  {
    vtkGenericWarningMacro("Error with the format version." << endl);
    return;
  }

  hid_t realScalarsId = H5Dopen(fileIndx, "real scalars");
  //
  // Read the real scalars
  //
  if (realScalarsId < 0)
  {
    vtkGenericWarningMacro("Real scalars not found in FLASH3." << endl);
    return;
  }

  hid_t spaceId = H5Dget_space(realScalarsId);
  if (spaceId < 0)
  {
    vtkGenericWarningMacro("Failed to get the real scalars space." << endl);
    return;
  }

  hsize_t scalarDims[10];
  H5Sget_simple_extent_dims(spaceId, scalarDims, nullptr);

  int nScalars = scalarDims[0];

  hid_t datatype = H5Tcreate(H5T_COMPOUND, sizeof(FlashReaderDoubleScalar));

  hid_t string20 = H5Tcopy(H5T_C_S1);
  H5Tset_size(string20, 20);

  H5Tinsert(datatype, "name", HOFFSET(FlashReaderDoubleScalar, Name), string20);
  H5Tinsert(datatype, "value", HOFFSET(FlashReaderDoubleScalar, Value), H5T_NATIVE_DOUBLE);

  std::vector<FlashReaderDoubleScalar> rs(nScalars);
  H5Dread(realScalarsId, datatype, H5S_ALL, H5S_ALL, H5P_DEFAULT, rs.data());

  for (int i = 0; i < nScalars; i++)
  {
    if (strncmp(rs[i].Name, "time", 4) == 0)
    {
      this->SimulationParameters.Time = rs[i].Value;
    }
  }

  H5Tclose(string20);
  H5Tclose(datatype);
  H5Sclose(spaceId);
  H5Dclose(realScalarsId);
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadIntegerScalars(hid_t fileIndx)
{
  // Should only be used for FLASH3 files

  if (this->FileFormatVersion < FLASH_READER_FLASH3_FFV8)
  {
    vtkGenericWarningMacro("Error with the format version." << endl);
    return;
  }

  hid_t intScalarsId = H5Dopen(fileIndx, "integer scalars");

  // Read the integer scalars
  if (intScalarsId < 0)
  {
    vtkGenericWarningMacro("Integer scalars not found in FLASH3." << endl);
    return;
  }

  hid_t spaceId = H5Dget_space(intScalarsId);
  if (spaceId < 0)
  {
    vtkGenericWarningMacro("Failed to get the integer scalars space." << endl);
    return;
  }

  hsize_t scalarDims[1];
  H5Sget_simple_extent_dims(spaceId, scalarDims, nullptr);
  int nScalars = scalarDims[0];

  hid_t datatype = H5Tcreate(H5T_COMPOUND, sizeof(FlashReaderIntegerScalar));

  hid_t string20 = H5Tcopy(H5T_C_S1);
  H5Tset_size(string20, 20);

  H5Tinsert(datatype, "name", HOFFSET(FlashReaderIntegerScalar, Name), string20);
  H5Tinsert(datatype, "value", HOFFSET(FlashReaderIntegerScalar, Value), H5T_NATIVE_INT);

  std::vector<FlashReaderIntegerScalar> is(nScalars);
  H5Dread(intScalarsId, datatype, H5S_ALL, H5S_ALL, H5P_DEFAULT, is.data());

  for (int i = 0; i < nScalars; i++)
  {
    if (strncmp(is[i].Name, "nxb", 3) == 0)
    {
      this->SimulationParameters.NumberOfXDivisions = is[i].Value;
    }
    else if (strncmp(is[i].Name, "nyb", 3) == 0)
    {
      this->SimulationParameters.NumberOfYDivisions = is[i].Value;
    }
    else if (strncmp(is[i].Name, "nzb", 3) == 0)
    {
      this->SimulationParameters.NumberOfZDivisions = is[i].Value;
    }
    else if (strncmp(is[i].Name, "globalnumblocks", 15) == 0)
    {
      this->SimulationParameters.NumberOfBlocks = is[i].Value;
    }
    else if (strncmp(is[i].Name, "nstep", 5) == 0)
    {
      this->SimulationParameters.NumberOfTimeSteps = is[i].Value;
    }
  }

  H5Tclose(string20);
  H5Tclose(datatype);
  H5Sclose(spaceId);
  H5Dclose(intScalarsId);
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadVersionInformation(hid_t fileIndx)
{
  // temporarily disable error reporting
  H5E_auto_t old_errorfunc;
  void* old_clientdata = nullptr;
  H5Eget_auto(&old_errorfunc, &old_clientdata);
  H5Eset_auto(nullptr, nullptr);

  // If this is a FLASH3 Particles file, or a FLASH3 file with particles,
  // then it will have the "particle names" field.  If, in addition, it's a
  // file format version (FFV) 9 file, it can have "file format version" and
  // "sim info", so further checking is needed.  Further checking is also
  // needed for non-particle files.  So...further checking all around.

  int flash3_particles = 0; //  Init to false
  hid_t h5_PN = H5Dopen(fileIndx, "particle names");
  if (h5_PN >= 0)
  {
    flash3_particles = 1;
    H5Dclose(h5_PN);
  }

  // Read the file format version  (<= 7 means FLASH2)
  hid_t h5_FFV = H5Dopen(fileIndx, "file format version");

  if (h5_FFV < 0)
  {
    hid_t h5_SI = H5Dopen(fileIndx, "sim info");
    if (h5_SI < 0)
    {
      if (flash3_particles == 1)
      {
        this->FileFormatVersion = FLASH_READER_FLASH3_FFV8;
      }
      else
      {
        this->FileFormatVersion = 7;
      }
    }
    else
    {
      // Read the "sim info" components
      hid_t si_type = H5Tcreate(H5T_COMPOUND, sizeof(FlashReaderSimulationInformation));
      H5Tinsert(si_type, "file format version",
        HOFFSET(FlashReaderSimulationInformation, FileFormatVersion), H5T_STD_I32LE);
      H5Tinsert(
        si_type, "setup call", HOFFSET(FlashReaderSimulationInformation, SetupCall), H5T_STRING);
      H5Tinsert(si_type, "file creation time",
        HOFFSET(FlashReaderSimulationInformation, FileCreationTime), H5T_STRING);
      H5Tinsert(si_type, "flash version", HOFFSET(FlashReaderSimulationInformation, FlashVersion),
        H5T_STRING);
      H5Tinsert(
        si_type, "build date", HOFFSET(FlashReaderSimulationInformation, BuildData), H5T_STRING);
      H5Tinsert(si_type, "build dir", HOFFSET(FlashReaderSimulationInformation, BuildDirectory),
        H5T_STRING);
      H5Tinsert(si_type, "build machine", HOFFSET(FlashReaderSimulationInformation, build_machine),
        H5T_STRING);
      H5Tinsert(si_type, "cflags", HOFFSET(FlashReaderSimulationInformation, CFlags), H5T_STRING);
      H5Tinsert(si_type, "fflags", HOFFSET(FlashReaderSimulationInformation, FFlags), H5T_STRING);
      H5Tinsert(si_type, "setup time stamp",
        HOFFSET(FlashReaderSimulationInformation, SetupTimeStamp), H5T_STRING);
      H5Tinsert(si_type, "build time stamp",
        HOFFSET(FlashReaderSimulationInformation, BuildTimeStamp), H5T_STRING);

      H5Dread(h5_SI, si_type, H5S_ALL, H5S_ALL, H5P_DEFAULT, &this->SimulationInformation);

      H5Tclose(si_type);
      H5Dclose(h5_SI);

      // FileFormatVersion is readin as little-endian. On BE machines, we need to
      // ensure that it's swapped back to right order.
      // The following will have no effect on LE machines.
      vtkByteSwap::SwapLE(&this->SimulationInformation.FileFormatVersion);
      this->FileFormatVersion = this->SimulationInformation.FileFormatVersion;
    }

    // turn back on error reporting
    H5Eset_auto(old_errorfunc, old_clientdata);
    old_clientdata = nullptr;
    return;
  }

  if (flash3_particles == 1)
  {
    this->FileFormatVersion = FLASH_READER_FLASH3_FFV8;
  }
  else
  {
    // FLASH 2 has file format version available in global attributes.
    H5Dread(h5_FFV, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, &this->FileFormatVersion);
  }

  H5Dclose(h5_FFV);

  // turn back on error reporting
  H5Eset_auto(old_errorfunc, old_clientdata);
  old_clientdata = nullptr;
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadSimulationParameters(hid_t fileIndx, bool bTmCycle)
{
  if (this->FileFormatVersion < FLASH_READER_FLASH3_FFV8)
  {
    // Read the simulation parameters
    hid_t simparamsId = H5Dopen(fileIndx, "simulation parameters");
    if (simparamsId < 0)
    {
      vtkGenericWarningMacro("Simulation parameters unavailable." << endl);
    }

    hid_t sp_type = H5Tcreate(H5T_COMPOUND, sizeof(FlashReaderSimulationParameters));

    H5Tinsert(sp_type, "total blocks", HOFFSET(FlashReaderSimulationParameters, NumberOfBlocks),
      H5T_NATIVE_INT);
    H5Tinsert(sp_type, "time", HOFFSET(FlashReaderSimulationParameters, Time), H5T_NATIVE_DOUBLE);
    H5Tinsert(
      sp_type, "timestep", HOFFSET(FlashReaderSimulationParameters, TimeStep), H5T_NATIVE_DOUBLE);
    H5Tinsert(
      sp_type, "redshift", HOFFSET(FlashReaderSimulationParameters, RedShift), H5T_NATIVE_DOUBLE);
    H5Tinsert(sp_type, "number of steps",
      HOFFSET(FlashReaderSimulationParameters, NumberOfTimeSteps), H5T_NATIVE_INT);
    H5Tinsert(
      sp_type, "nxb", HOFFSET(FlashReaderSimulationParameters, NumberOfXDivisions), H5T_NATIVE_INT);
    H5Tinsert(
      sp_type, "nyb", HOFFSET(FlashReaderSimulationParameters, NumberOfYDivisions), H5T_NATIVE_INT);
    H5Tinsert(
      sp_type, "nzb", HOFFSET(FlashReaderSimulationParameters, NumberOfZDivisions), H5T_NATIVE_INT);

    H5Dread(simparamsId, sp_type, H5S_ALL, H5S_ALL, H5P_DEFAULT, &this->SimulationParameters);

    H5Tclose(sp_type);
    H5Dclose(simparamsId);
  }
  else
  {
    this->ReadIntegerScalars(fileIndx);
    this->ReadDoubleScalars(fileIndx);
  }

  if (bTmCycle)
  {
    return;
  }

  // Sanity check: size of the gid array better match number of blocks
  //               reported in the simulation parameters
  if (this->SimulationParameters.NumberOfBlocks != this->NumberOfBlocks)
  {
    vtkGenericWarningMacro("Inconsistency in the number of blocks." << endl);
    return;
  }

  if (this->SimulationParameters.NumberOfXDivisions == 1)
  {
    this->BlockGridDimensions[0] = 1;
    this->BlockCellDimensions[0] = 1;
  }
  else
  {
    this->BlockGridDimensions[0] = this->SimulationParameters.NumberOfXDivisions + 1;
    this->BlockCellDimensions[0] = this->SimulationParameters.NumberOfXDivisions;
  }

  if (this->SimulationParameters.NumberOfYDivisions == 1)
  {
    this->BlockGridDimensions[1] = 1;
    this->BlockCellDimensions[1] = 1;
  }
  else
  {
    this->BlockGridDimensions[1] = this->SimulationParameters.NumberOfYDivisions + 1;
    this->BlockCellDimensions[1] = this->SimulationParameters.NumberOfYDivisions;
  }

  if (this->SimulationParameters.NumberOfZDivisions == 1)
  {
    this->BlockGridDimensions[2] = 1;
    this->BlockCellDimensions[2] = 1;
  }
  else
  {
    this->BlockGridDimensions[2] = this->SimulationParameters.NumberOfZDivisions + 1;
    this->BlockCellDimensions[2] = this->SimulationParameters.NumberOfZDivisions;
  }
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::GetBlockMinMaxGlobalDivisionIds()
{
  double problemsize[3] = { this->MaxBounds[0] - this->MinBounds[0],
    this->MaxBounds[1] - this->MinBounds[1], this->MaxBounds[2] - this->MinBounds[2] };

  for (int b = 0; b < this->NumberOfBlocks; b++)
  {
    Block& B = this->Blocks[b];

    for (int d = 0; d < 3; d++)
    {
      if (d < this->NumberOfDimensions)
      {
        double factor = problemsize[d] / (B.MaxBounds[d] - B.MinBounds[d]);
        double start = (B.MinBounds[d] - this->MinBounds[d]) / problemsize[d];

        double beg = this->BlockCellDimensions[d] * start * factor;
        double end = this->BlockCellDimensions[d] * start * factor + this->BlockCellDimensions[d];
        this->Blocks[b].MinGlobalDivisionIds[d] = int(beg + 0.5);
        this->Blocks[b].MaxGlobalDivisionIds[d] = int(end + 0.5);
      }
      else
      {
        this->Blocks[b].MinGlobalDivisionIds[d] = 0;
        this->Blocks[b].MaxGlobalDivisionIds[d] = 0;
      }
    }
  }
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadBlockTypes()
{
  // Read the node type description for the blocks
  hid_t nodetypeId = H5Dopen(this->FileIndex, "node type");
  if (nodetypeId < 0)
  {
    vtkGenericWarningMacro("Block types not found." << endl);
    return;
  }

  hid_t nodetypeSpaceId = H5Dget_space(nodetypeId);

  hsize_t nodetype_dims[1];
  hsize_t nodetype_ndims = H5Sget_simple_extent_dims(nodetypeSpaceId, nodetype_dims, nullptr);

  if (static_cast<int>(nodetype_ndims) != 1 ||
    static_cast<int>(nodetype_dims[0]) != this->NumberOfBlocks)
  {
    vtkGenericWarningMacro("Inconsistency in the number of blocks." << endl);
    return;
  }

  hid_t nodetype_raw_data_type = H5Dget_type(nodetypeId);
  hid_t nodetype_data_type = H5Tget_native_type(nodetype_raw_data_type, H5T_DIR_ASCEND);

  std::vector<int> nodetype_array(this->NumberOfBlocks);
  H5Dread(nodetypeId, nodetype_data_type, H5S_ALL, H5S_ALL, H5P_DEFAULT, nodetype_array.data());

  this->NumberOfLeafBlocks = 0;
  for (int b = 0; b < this->NumberOfBlocks; b++)
  {
    int ntype = nodetype_array[b];
    this->Blocks[b].Type = ntype;
    if (ntype == FLASH_READER_LEAF_BLOCK)
    {
      this->NumberOfLeafBlocks++;
      this->LeafBlocks.push_back(b);
    }
  }

  H5Tclose(nodetype_data_type);
  H5Tclose(nodetype_raw_data_type);
  H5Sclose(nodetypeSpaceId);
  H5Dclose(nodetypeId);
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadBlockBounds()
{
  // Read the bounding box description for the blocks
  hid_t bboxId = H5Dopen(this->FileIndex, "bounding box");
  if (bboxId < 0)
  {
    vtkGenericWarningMacro("Blocks bounding info not found." << endl);
    return;
  }

  hid_t bboxSpaceId = H5Dget_space(bboxId);
  hsize_t bbox_dims[3];
  hsize_t bbox_ndims = H5Sget_simple_extent_dims(bboxSpaceId, bbox_dims, nullptr);

  if (this->FileFormatVersion <= FLASH_READER_FLASH3_FFV8)
  {
    if (static_cast<int>(bbox_ndims) != 3 ||
      static_cast<int>(bbox_dims[0]) != this->NumberOfBlocks ||
      static_cast<int>(bbox_dims[1]) != this->NumberOfDimensions ||
      static_cast<int>(bbox_dims[2]) != 2)
    {
      vtkGenericWarningMacro("Error with number of blocks "
        << "or number of dimensions." << endl);
      return;
    }

    std::vector<double> bbox_array(this->NumberOfBlocks * this->NumberOfDimensions * 2);
    H5Dread(bboxId, H5T_NATIVE_DOUBLE, H5S_ALL, H5S_ALL, H5P_DEFAULT, bbox_array.data());

    this->MinBounds[0] = VTK_DOUBLE_MAX;
    this->MinBounds[1] = VTK_DOUBLE_MAX;
    this->MinBounds[2] = VTK_DOUBLE_MAX;
    this->MaxBounds[0] = -VTK_DOUBLE_MAX;
    this->MaxBounds[1] = -VTK_DOUBLE_MAX;
    this->MaxBounds[2] = -VTK_DOUBLE_MAX;

    for (int b = 0; b < this->NumberOfBlocks; b++)
    {
      double* bbox_line = bbox_array.data() + this->NumberOfDimensions * 2 * b;
      for (int d = 0; d < 3; d++)
      {
        if (d + 1 <= this->NumberOfDimensions)
        {
          this->Blocks[b].MinBounds[d] = bbox_line[d * 2 + 0];
          this->Blocks[b].MaxBounds[d] = bbox_line[d * 2 + 1];
        }
        else
        {
          this->Blocks[b].MinBounds[d] = 0;
          this->Blocks[b].MaxBounds[d] = 0;
        }

        if (this->Blocks[b].MinBounds[0] < this->MinBounds[0])
        {
          this->MinBounds[0] = this->Blocks[b].MinBounds[0];
        }

        if (this->Blocks[b].MinBounds[1] < this->MinBounds[1])
        {
          this->MinBounds[1] = this->Blocks[b].MinBounds[1];
        }

        if (this->Blocks[b].MinBounds[2] < this->MinBounds[2])
        {
          this->MinBounds[2] = this->Blocks[b].MinBounds[2];
        }

        if (this->Blocks[b].MaxBounds[0] > this->MaxBounds[0])
        {
          this->MaxBounds[0] = this->Blocks[b].MaxBounds[0];
        }

        if (this->Blocks[b].MaxBounds[1] > this->MaxBounds[1])
        {
          this->MaxBounds[1] = this->Blocks[b].MaxBounds[1];
        }

        if (this->Blocks[b].MaxBounds[2] > this->MaxBounds[2])
        {
          this->MaxBounds[2] = this->Blocks[b].MaxBounds[2];
        }
      }

      bbox_line = nullptr;
    }
  }
  else if (this->FileFormatVersion == FLASH_READER_FLASH3_FFV9)
  {
    if (static_cast<int>(bbox_ndims) != 3 ||
      static_cast<int>(bbox_dims[0]) != this->NumberOfBlocks ||
      static_cast<int>(bbox_dims[1]) != FLASH_READER_MAX_DIMS ||
      static_cast<int>(bbox_dims[2]) != 2)
    {
      vtkGenericWarningMacro("Error with number of blocks." << endl);
      return;
    }

    std::vector<double> bbox_array(this->NumberOfBlocks * FLASH_READER_MAX_DIMS * 2);
    H5Dread(bboxId, H5T_NATIVE_DOUBLE, H5S_ALL, H5S_ALL, H5P_DEFAULT, bbox_array.data());

    this->MinBounds[0] = VTK_DOUBLE_MAX;
    this->MinBounds[1] = VTK_DOUBLE_MAX;
    this->MinBounds[2] = VTK_DOUBLE_MAX;
    this->MaxBounds[0] = -VTK_DOUBLE_MAX;
    this->MaxBounds[1] = -VTK_DOUBLE_MAX;
    this->MaxBounds[2] = -VTK_DOUBLE_MAX;

    for (int b = 0; b < this->NumberOfBlocks; b++)
    {
      double* bbox_line = bbox_array.data() + FLASH_READER_MAX_DIMS * 2 * b;

      for (int d = 0; d < 3; d++)
      {
        this->Blocks[b].MinBounds[d] = bbox_line[d * 2 + 0];
        this->Blocks[b].MaxBounds[d] = bbox_line[d * 2 + 1];

        if (this->Blocks[b].MinBounds[0] < this->MinBounds[0])
        {
          this->MinBounds[0] = this->Blocks[b].MinBounds[0];
        }

        if (this->Blocks[b].MinBounds[1] < this->MinBounds[1])
        {
          this->MinBounds[1] = this->Blocks[b].MinBounds[1];
        }

        if (this->Blocks[b].MinBounds[2] < this->MinBounds[2])
        {
          this->MinBounds[2] = this->Blocks[b].MinBounds[2];
        }

        if (this->Blocks[b].MaxBounds[0] > this->MaxBounds[0])
        {
          this->MaxBounds[0] = this->Blocks[b].MaxBounds[0];
        }

        if (this->Blocks[b].MaxBounds[1] > this->MaxBounds[1])
        {
          this->MaxBounds[1] = this->Blocks[b].MaxBounds[1];
        }

        if (this->Blocks[b].MaxBounds[2] > this->MaxBounds[2])
        {
          this->MaxBounds[2] = this->Blocks[b].MaxBounds[2];
        }
      }

      bbox_line = nullptr;
    }
  }

  H5Sclose(bboxSpaceId);
  H5Dclose(bboxId);
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadBlockCenters()
{
  // Read the coordinates description for the blocks
  hid_t coordinatesId = H5Dopen(this->FileIndex, "coordinates");
  if (coordinatesId < 0)
  {
    vtkGenericWarningMacro("Block centers not found." << endl);
    return;
  }

  hid_t coordinatesSpaceId = H5Dget_space(coordinatesId);

  hsize_t coordinates_dims[2];
  hsize_t coordinates_ndims =
    H5Sget_simple_extent_dims(coordinatesSpaceId, coordinates_dims, nullptr);

  if (this->FileFormatVersion <= FLASH_READER_FLASH3_FFV8)
  {
    if (static_cast<int>(coordinates_ndims) != 2 ||
      static_cast<int>(coordinates_dims[0]) != this->NumberOfBlocks ||
      static_cast<int>(coordinates_dims[1]) != this->NumberOfDimensions)
    {
      vtkGenericWarningMacro("Error with number of blocks or "
        << "number of dimensions." << endl);
      return;
    }

    std::vector<double> coordinates_array(this->NumberOfBlocks * this->NumberOfDimensions);
    H5Dread(
      coordinatesId, H5T_NATIVE_DOUBLE, H5S_ALL, H5S_ALL, H5P_DEFAULT, coordinates_array.data());

    for (int b = 0; b < this->NumberOfBlocks; b++)
    {
      double* coords = coordinates_array.data() + this->NumberOfDimensions * b;

      if (this->NumberOfDimensions == 1)
      {
        this->Blocks[b].Center[0] = coords[0];
        this->Blocks[b].Center[1] = 0.0;
        this->Blocks[b].Center[2] = 0.0;
      }
      else if (this->NumberOfDimensions == 2)
      {
        this->Blocks[b].Center[0] = coords[0];
        this->Blocks[b].Center[1] = coords[1];
        this->Blocks[b].Center[2] = 0.0;
      }
      else if (this->NumberOfDimensions == 3)
      {
        this->Blocks[b].Center[0] = coords[0];
        this->Blocks[b].Center[1] = coords[1];
        this->Blocks[b].Center[2] = coords[2];
      }

      coords = nullptr;
    }
  }
  else if (this->FileFormatVersion == FLASH_READER_FLASH3_FFV9)
  {
    if (static_cast<int>(coordinates_ndims) != 2 ||
      static_cast<int>(coordinates_dims[0]) != this->NumberOfBlocks ||
      static_cast<int>(coordinates_dims[1]) != FLASH_READER_MAX_DIMS)
    {
      vtkGenericWarningMacro("Error with number of blocks." << endl);
      return;
    }

    std::vector<double> coordinates_array(this->NumberOfBlocks * FLASH_READER_MAX_DIMS);
    H5Dread(
      coordinatesId, H5T_NATIVE_DOUBLE, H5S_ALL, H5S_ALL, H5P_DEFAULT, coordinates_array.data());

    for (int b = 0; b < this->NumberOfBlocks; b++)
    {
      double* coords = coordinates_array.data() + FLASH_READER_MAX_DIMS * b;
      this->Blocks[b].Center[0] = coords[0];
      this->Blocks[b].Center[1] = coords[1];
      this->Blocks[b].Center[2] = coords[2];
      coords = nullptr;
    }
  }

  H5Sclose(coordinatesSpaceId);
  H5Dclose(coordinatesId);
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadBlockStructures()
{
  // temporarily disable error reporting
  H5E_auto_t old_errorfunc;
  void* old_clientdata = nullptr;
  H5Eget_auto(&old_errorfunc, &old_clientdata);
  H5Eset_auto(nullptr, nullptr);

  // Read the "gid" block connectivity description
  hid_t gidId = H5Dopen(this->FileIndex, "gid");

  // turn back on error reporting
  H5Eset_auto(old_errorfunc, old_clientdata);

  if (gidId < 0)
  {
    this->NumberOfBlocks = 0;
    old_clientdata = nullptr;
    return;
  }

  hid_t gidSpaceId = H5Dget_space(gidId);

  hsize_t gid_dims[2];
  hsize_t gid_ndims = H5Sget_simple_extent_dims(gidSpaceId, gid_dims, nullptr);
  if (gid_ndims != 2)
  {
    vtkGenericWarningMacro("Error with reading block connectivity." << endl);
    return;
  }

  this->NumberOfBlocks = gid_dims[0];
  switch (gid_dims[1])
  {
    case 5:
      this->NumberOfDimensions = 1;
      this->NumberOfChildrenPerBlock = 2;
      this->NumberOfNeighborsPerBlock = 2;
      break;

    case 9:
      this->NumberOfDimensions = 2;
      this->NumberOfChildrenPerBlock = 4;
      this->NumberOfNeighborsPerBlock = 4;
      break;

    case 15:
      this->NumberOfDimensions = 3;
      this->NumberOfChildrenPerBlock = 8;
      this->NumberOfNeighborsPerBlock = 6;
      break;

    default:
      vtkGenericWarningMacro("Invalid block connectivity." << endl);
      break;
  }

  hid_t gid_raw_data_type = H5Dget_type(gidId);
  hid_t gid_data_type = H5Tget_native_type(gid_raw_data_type, H5T_DIR_ASCEND);

  std::vector<int> gid_array(this->NumberOfBlocks * gid_dims[1]);
  H5Dread(gidId, gid_data_type, H5S_ALL, H5S_ALL, H5P_DEFAULT, gid_array.data());

  // convert to an easier-to-grok format
  this->Blocks.resize(this->NumberOfBlocks);
  for (int b = 0; b < this->NumberOfBlocks; b++)
  {
    int* gid_line = gid_array.data() + gid_dims[1] * b;
    int pos = 0;
    int n;

    this->Blocks[b].Index = b + 1; // 1-origin IDs

    for (n = 0; n < 6; n++)
    {
      this->Blocks[b].NeighborIds[n] = -32;
    }

    for (n = 0; n < this->NumberOfNeighborsPerBlock; n++)
    {
      this->Blocks[b].NeighborIds[n] = gid_line[pos++];
    }

    this->Blocks[b].ParentId = gid_line[pos++];

    for (n = 0; n < 8; n++)
    {
      this->Blocks[b].ChildrenIds[n] = -1;
    }

    for (n = 0; n < this->NumberOfChildrenPerBlock; n++)
    {
      this->Blocks[b].ChildrenIds[n] = gid_line[pos++];
    }

    gid_line = nullptr;
  }

  H5Tclose(gid_data_type);
  H5Tclose(gid_raw_data_type);
  H5Sclose(gidSpaceId);
  H5Dclose(gidId);
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadRefinementLevels()
{
  // Read the bounding box description for the blocks
  hid_t refinementId = H5Dopen(this->FileIndex, "refine level");
  if (refinementId < 0)
  {
    vtkGenericWarningMacro("Refinement levels not found." << endl);
    return;
  }

  hid_t refinementSpaceId = H5Dget_space(refinementId);

  hsize_t refinement_dims[1];
  hsize_t refinement_ndims = H5Sget_simple_extent_dims(refinementSpaceId, refinement_dims, nullptr);

  if (static_cast<int>(refinement_ndims) != 1 ||
    static_cast<int>(refinement_dims[0]) != this->NumberOfBlocks)
  {
    vtkGenericWarningMacro("Error with number of blocks" << endl);
    return;
  }

  hid_t refinement_raw_data_type = H5Dget_type(refinementId);
  hid_t refinement_data_type = H5Tget_native_type(refinement_raw_data_type, H5T_DIR_ASCEND);

  std::vector<int> refinement_array(this->NumberOfBlocks);
  H5Dread(
    refinementId, refinement_data_type, H5S_ALL, H5S_ALL, H5P_DEFAULT, refinement_array.data());

  for (int b = 0; b < this->NumberOfBlocks; b++)
  {
    int level = refinement_array[b];
    this->Blocks[b].Level = level;
    if (level > this->NumberOfLevels)
    {
      this->NumberOfLevels = level;
    }
  }

  H5Tclose(refinement_data_type);
  H5Tclose(refinement_raw_data_type);
  H5Sclose(refinementSpaceId);
  H5Dclose(refinementId);
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadDataAttributeNames()
{
  hid_t unknownsId = H5Dopen(this->FileIndex, "unknown names");
  if (unknownsId < 0)
  {
    vtkGenericWarningMacro("Data attributes not found." << endl);
    return;
  }

  hid_t unkSpaceId = H5Dget_space(unknownsId);

  hsize_t unk_dims[2];
  hsize_t unk_ndims = H5Sget_simple_extent_dims(unkSpaceId, unk_dims, nullptr);
  if (unk_ndims != 2 || unk_dims[1] != 1)
  {
    vtkGenericWarningMacro("Error with reading data attributes." << endl);
    return;
  }

  hid_t unk_raw_data_type = H5Dget_type(unknownsId);
  int length = (int)(H5Tget_size(unk_raw_data_type));

  int nvars = unk_dims[0];
  std::vector<char> unk_array(nvars * length);

  H5Dread(unknownsId, unk_raw_data_type, H5S_ALL, H5S_ALL, H5P_DEFAULT, unk_array.data());

  this->AttributeNames.resize(nvars);
  std::vector<char> tmpstring(length + 1);
  for (int v = 0; v < nvars; v++)
  {
    for (int c = 0; c < length; c++)
    {
      tmpstring[c] = unk_array[v * length + c];
    }
    tmpstring[length] = '\0';

    this->AttributeNames[v] = tmpstring.data();
  }

  H5Tclose(unk_raw_data_type);
  H5Sclose(unkSpaceId);
  H5Dclose(unknownsId);
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadParticlesComponent(
  hid_t dataIndx, const char* compName, double* dataBuff)
{
  if (!compName || this->FileFormatVersion < FLASH_READER_FLASH3_FFV8)
  {
    vtkGenericWarningMacro("Invalid component name of particles or "
      << "non FLASH3_FFV8 file format." << endl);
    return;
  }

  hsize_t spaceIdx = H5Dget_space(dataIndx); // data space index
  hsize_t thisSize = this->NumberOfParticles;
  hsize_t spaceMem = H5Screate_simple(1, &thisSize, nullptr);
  int attrIndx = this->ParticleAttributeNamesToIds[compName];

  hsize_t theShift[2] = { 0, static_cast<hsize_t>(attrIndx) };
  hsize_t numReads[2] = { static_cast<hsize_t>(this->NumberOfParticles), 1 };
  H5Sselect_hyperslab(spaceIdx, H5S_SELECT_SET, theShift, nullptr, numReads, nullptr);
  H5Dread(dataIndx, H5T_NATIVE_DOUBLE, spaceMem, spaceIdx, H5P_DEFAULT, dataBuff);

  H5Sclose(spaceIdx);
  H5Sclose(spaceMem);
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadParticleAttributes()
{
  // temporarily disable error reporting
  H5E_auto_t old_errorfunc;
  void* old_clientdata = nullptr;
  H5Eget_auto(&old_errorfunc, &old_clientdata);
  H5Eset_auto(nullptr, nullptr);

  // find the particle variable (if it exists)
  hid_t pointId;
  this->ParticleName = "particle tracers";
  pointId = H5Dopen(this->FileIndex, this->ParticleName.c_str());
  if (pointId < 0)
  {
    this->ParticleName = "tracer particles";
    pointId = H5Dopen(this->FileIndex, this->ParticleName.c_str());
  }

  // turn back on error reporting
  H5Eset_auto(old_errorfunc, old_clientdata);

  if (pointId < 0)
  {
    this->NumberOfParticles = 0;
    old_clientdata = nullptr;
    return;
  }

  hid_t pointSpaceId = H5Dget_space(pointId);

  hsize_t p_dims[100];
  hsize_t p_ndims = H5Sget_simple_extent_dims(pointSpaceId, p_dims, nullptr);
  if (p_ndims != 1)
  {
    vtkGenericWarningMacro("Error with number of data attributes." << endl);
  }

  this->NumberOfParticles = p_dims[0];

  hid_t point_raw_type = H5Dget_type(pointId);
  int numMembers = H5Tget_nmembers(point_raw_type);
  for (int i = 0; i < numMembers; i++)
  {
    char* member_name = H5Tget_member_name(point_raw_type, i);
    std::string nice_name = GetSeparatedParticleName(member_name);
    hid_t member_raw_type = H5Tget_member_type(point_raw_type, i);
    hid_t member_type = H5Tget_native_type(member_raw_type, H5T_DIR_ASCEND);
    int index = (int)(this->ParticleAttributeTypes.size());

    if (strcmp(member_name, "particle_x") && strcmp(member_name, "particle_y") &&
      strcmp(member_name, "particle_z"))
    {
      if (H5Tequal(member_type, H5T_NATIVE_DOUBLE) > 0)
      {
        this->ParticleAttributeTypes.push_back(H5T_NATIVE_DOUBLE);
        this->ParticleAttributeNames.emplace_back(member_name);
        this->ParticleAttributeNamesToIds[nice_name] = index;
      }
      else if (H5Tequal(member_type, H5T_NATIVE_INT) > 0)
      {
        this->ParticleAttributeTypes.push_back(H5T_NATIVE_INT);
        this->ParticleAttributeNames.emplace_back(member_name);
        this->ParticleAttributeNamesToIds[nice_name] = index;
      }
      else
      {
        vtkGenericWarningMacro("Only DOUBLE and INT supported." << endl);
      }
    }

    // We read the particles before the grids.  Just in case we
    // don't have any grids, take a stab at the problem dimension
    // based purely on the existence of various data members.
    // This will be overwritten by the true grid topological
    // dimension if the grid exists.
    if (strcmp(member_name, "particle_x") == 0 && this->NumberOfDimensions < 1)
    {
      this->NumberOfDimensions = 1;
    }

    if (strcmp(member_name, "particle_y") == 0 && this->NumberOfDimensions < 2)
    {
      this->NumberOfDimensions = 2;
    }

    if (strcmp(member_name, "particle_z") == 0 && this->NumberOfDimensions < 3)
    {
      this->NumberOfDimensions = 3;
    }

    member_name = nullptr;

    H5Tclose(member_type);
    H5Tclose(member_raw_type);
  }

  H5Tclose(point_raw_type);
  H5Sclose(pointSpaceId);
  H5Dclose(pointId);
}

//------------------------------------------------------------------------------
void vtkFlashReaderInternal::ReadParticleAttributesFLASH3()
{
  // Should only be used for FLASH3 files
  if (this->FileFormatVersion < FLASH_READER_FLASH3_FFV8)
  {
    return;
  }

  // temporarily disable error reporting
  H5E_auto_t old_errorfunc;
  void* old_clientdata = nullptr;
  H5Eget_auto(&old_errorfunc, &old_clientdata);
  H5Eset_auto(nullptr, nullptr);

  hid_t pnameId = H5Dopen(this->FileIndex, "particle names");

  // turn back on error reporting
  H5Eset_auto(old_errorfunc, old_clientdata);

  if (pnameId < 0)
  {
    this->NumberOfParticles = 0;
    old_clientdata = nullptr;
    return;
  }

  hid_t pnamespace = H5Dget_space(pnameId);
  hsize_t dims[10];
  hsize_t ndims = H5Sget_simple_extent_dims(pnamespace, dims, nullptr);

  // particle names ndims should be 2, and if the second dim isn't 1,
  // need to come up with a way to handle it!
  if (ndims != 2 || dims[1] != 1)
  {
    if (ndims != 2)
    {
      vtkGenericWarningMacro("FLASH3 expecting particle names ndims of 2, got " << ndims << endl);
    }
    if (dims[1] != 1)
    {
      vtkGenericWarningMacro(
        "FLASH3 expecting particle names dims[1] of 1, got " << dims[1] << endl);
    }
  }

  int numNames = dims[0];

  // create the right-size string, and a char array to read the data into
  hid_t string24 = H5Tcopy(H5T_C_S1);
  H5Tset_size(string24, 24);
  std::vector<char> cnames(24 * numNames);
  H5Dread(pnameId, string24, H5S_ALL, H5S_ALL, H5P_DEFAULT, cnames.data());

  // Convert the single string to individual variable names.
  std::string snames(cnames.data());

  for (int i = 0; i < numNames; i++)
  {
    std::string name = snames.substr(i * 24, 24);

    int sp = (int)(name.find_first_of(' '));
    if (sp < 24)
    {
      name = name.substr(0, sp);
    }

    if (name != "particle_x" && name != "particle_y" && name != "particle_z")
    {
      std::string nice_name = GetSeparatedParticleName(name);
      this->ParticleAttributeTypes.push_back(H5T_NATIVE_DOUBLE);
      this->ParticleAttributeNames.push_back(name);
      this->ParticleAttributeNamesToIds[nice_name] = i;
    }

    // We read the particles before the grids.  Just in case we
    // don't have any grids, take a stab at the problem dimension
    // based purely on the existence of various data members.
    // This will be overwritten by the true grid topological
    // dimension if the grid exists.
    if (name == "posx" && this->NumberOfDimensions < 1)
    {
      this->NumberOfDimensions = 1;
    }

    if (name == "posy" && this->NumberOfDimensions < 2)
    {
      this->NumberOfDimensions = 2;
    }

    if (name == "posz" && this->NumberOfDimensions < 3)
    {
      this->NumberOfDimensions = 3;
    }
  }

  H5Tclose(string24);
  H5Sclose(pnamespace);
  H5Dclose(pnameId);

  // Read particle dimensions and particle HDFVarName

  // temporarily disable error reporting
  H5Eget_auto(&old_errorfunc, &old_clientdata);
  H5Eset_auto(nullptr, nullptr);

  // find the particle variable (if it exists)
  hid_t pointId;
  this->ParticleName = "particle tracers";
  pointId = H5Dopen(this->FileIndex, this->ParticleName.c_str());
  if (pointId < 0)
  {
    this->ParticleName = "tracer particles";
    pointId = H5Dopen(this->FileIndex, this->ParticleName.c_str());
  }

  // turn back on error reporting
  H5Eset_auto(old_errorfunc, old_clientdata);

  // Doesn't exist?  No problem -- we just don't have any particles
  if (pointId < 0)
  {
    vtkGenericWarningMacro("FLASH3 no tracer particles" << endl);
    this->NumberOfParticles = 0;
    old_clientdata = nullptr;
    return;
  }

  hid_t pointSpaceId = H5Dget_space(pointId);

  hsize_t p_dims[10];
  hsize_t p_ndims = H5Sget_simple_extent_dims(pointSpaceId, p_dims, nullptr);
  if (p_ndims != 2)
  {
    vtkGenericWarningMacro("FLASH3, expecting particle tracer ndims of 2, got" << p_ndims << endl);
  }
  this->NumberOfParticles = p_dims[0];

  H5Sclose(pointSpaceId);
  H5Dclose(pointId);
}
